MAHAYANA BUDDHISM

A View on Buddhism -Introduction to Buddhist practice and meditation, philosophy, history and traditions; especially Tibetan Buddhism.
Buddha Village - A Place For Buddhist Friends To Meet 
Buddha Brothers
Buddhist Supplies - Everything you need for your meditation practice
Dharma Shop - supporting Tibetan artisans by buying directly from Tibetan communities in Nepal and India

Garchen Buddhist Institute - Online Buddhist Bookstore
Medicine Buddha: Tibetan Buddhist teachings, individual & Group retreats, facility rentals, meditation, nature trails etc.
Monasteries of Tibet
Interesting facts about Buddhism and some commonly used terms.
Tibetan Buddhism - The Government of Tibet in exile
Topics on Buddhism - A site dedicated to Tibetan Buddhism
Diamond Way of Buddhism - A service of the Karma Kagyu Lineage of Tibetan Buddhism.